CDISC-Gloss – A variable in a model, or a variable that wholly or partially characterizes a probability distribution (mathematics and statistics).
NOTE: in clinical trials the term is often used synonymously with ‘variable’ for factual information (age, date of recovery), measurements, and clinical assessments. It is most appropriately linked to statistical conventions and as a numeric characteristic of a population. Parameters are rarely known and are usually estimated by statistical computation from samples. Thus, the term is narrower than variable. [Parexel Barnett; ADaM; HyperStat Online] See also variable, outcome.